In recent years, in view of environmental protection, a high-output and high-capacity power source has been demanded for applying to low-emission vehicles such as electric vehicles and hybrid cars. Moreover, other than the automotive field, with global diffusion of mobile devices such as information equipment and telecommunication equipment, secondary batteries which enable to enhance the performance of the mobile devices higher has been required.
Among secondary batteries, a solid-state battery using an inorganic solid electrolyte is particularly excellent in its safety and reliability, compared with a battery having an organic electrolyte using flammable organic solvent. As the solid-state battery, for example, Patent literatures 1 to 4 propose solid-state batteries which use sulfide-based crystallized glass as the solid electrolyte. The sulfide-based solid electrolyte shows high ion conductivity and is capable of enhancing the performance of the solid-state battery higher. However, the sulfide-based solid electrolyte shows low water resistance so that it tends to react with water and produce hydrogen sulfide; whereby ion conductivity of the solid electrolyte declines and the battery is deteriorated. Hence, when using sulfide-based solid electrolyte, to obtain a battery which exhibits excellent safety and reliability, a means for inhibiting reaction with water and a means for detecting deterioration of the battery must be provided.
On the other hand, Patent literature 5 proposes an all-solid-state secondary battery, wherein a hydrogen sulfide detector is arranged in an exterior body of the solid-state battery to be able to detect hydrogen sulfide generated within the battery.